4 
Colorado Experiment Station 
correct, of which we had no doubt at the time, for we have a 
great deal of confidence in the common judgment of a community, 
we proposed to try to find out the reasons for them. 
The subject itself pertaining to the causes for differences in 
the properties and composition of wheats is really an old one, 
and has been studied by so many very able men that our proposal 
to take up this question as it applies to Colorado wheat provoked 
a smile, but permission to undertake it was given, and the follow¬ 
ing pages present our endeavor to make our views and result 
known to the Colorado wheat grower. 
CLIMATE AND SOIL IMPORTANT FACTORS 
There are two big groups of factors concerned in the produc¬ 
tion of a crop of wheat. This much is very evident and agreed 
to by all parties. The first group comprises the climatic factors; 
the second the soil factors. In the first group we have all of those 
factors which we often express as weather, such as temperature, 
rainfall and winds. In the second group we have the actual content 
of the soil in plant food and the ratios in which these foods 
exist in the soil and the forms in which they may be present, i. e., 
whether the plant can take them up easily enough to produce 
the best results or not. We also have the mechanical and physical 
properties of the soil, its deportment toward moisture, whether 
it is retentive of it, whether it puddles, bakes and cracks or not. 
These are all things that the farmer knows when he comes to 
think of them. 
OTHER FACTORS 
There are still other things that he knows, one of which, for 
instance, is that a few, only three or four, wet, muggy, warm days, 
just before the wheat ripens, will practically spoil his crop. Many 
of us have seen heavy dews, or a few hours of fogginess, produce 
the same result, and we rightly believe that it was not the wet’ 
nor the heat, nor the cloudiness in themselves that did the damage, 
but it was because rust developed under these conditions. The 
farmer knows that when the rust comes on his wheat that the 
grains of wheat will be shrunken and will not sell so well, in 
fact, will be inferior. This is an indirect result of unfavorable 
weather. If there were no rust plants growing in the country, 
and consequently no rust spores, ready to germinate, the warm 
muggy weather would probably do very little, or no harm at all. 
The weather in an indirect way may mean more than it does by its 
direct action, for the wheat plant itself, as well as the rust plant, 
will not grow if the weather be unfavorable. A hot, dry wind 
